CN110047449B

CN110047449B - Display device and electronic apparatus

Info

Publication number: CN110047449B
Application number: CN201910208418.4A
Authority: CN
Inventors: 日高幸德; 大塚健; 木下直人
Original assignee: Sony Corp
Current assignee: Sony Corp
Priority date: 2013-09-25
Filing date: 2014-09-02
Publication date: 2021-12-31
Anticipated expiration: 2034-09-02
Also published as: JPWO2015045752A1; CN110082940A; CN110082940B; EP3032525B1; US10854150B2; EP3032525A4; EP3032525A1; US20180336851A1; CN105556585B; CN110047449A; WO2015045752A1; US20160232856A1; US10026368B2; CN105556585A; JP6424824B2

Abstract

A display device and an electronic apparatus are provided. The display device is provided with a display unit (11) having a first display surface and a second display surface (S1, S2) facing each other. The display unit (11) has a first display panel (111) arranged on the first display surface (S1) side and including a plurality of light emitting elements, and a second display panel (112) arranged on the second display surface (S2) side and including a plurality of light control elements that perform light control for controlling transmission or reflection of incident light and also perform reflected image display using reflection of incident light.

Description

Display device and electronic apparatus

The present application is a divisional application of a chinese national phase application of PCT applications international application numbers PCT/JP2014/073015,

application dates

2014, 9 and 2, 2016, 3 and 18, 2016, and invented name "display device and electronic device", and the chinese national phase application has an application number of 201480051786.8.

Technical Field

The present disclosure relates to a display device having a display portion including two types of display panels, and an electronic apparatus having such a display device.

Background

Conventionally, various types of display devices have been proposed. For example, patent document 1 discloses a display device using two types of display panels (display bodies).

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 2004-302321

Disclosure of Invention

Meanwhile, in general, a display device is desired to improve user convenience. Therefore, technical proposals for improving user convenience are desired.

Accordingly, it is desirable to provide a display device and an electronic apparatus capable of improving user convenience.

A display device according to an embodiment of the present disclosure includes: a display section having a first display surface and a second display surface facing each other. The display unit includes: a first display panel arranged on a first display surface side and including a plurality of light emitting elements; and a second display panel arranged on the second display surface side and including a plurality of light control elements that respectively perform light control for transmission or reflection control of incident light, and respectively perform reflection image display with reflection of the incident light.

An electronic device according to an embodiment of the present disclosure includes the display device according to the above-described embodiment of the present disclosure.

In the display device and the electronic apparatus of the embodiments of the present disclosure, image display on the first display surface and the second display surface facing each other is realized by using the first display panel and the second display panel. Further, since the first display panel is configured to include the above-described light emitting element and the second display panel is configured to include the above-described light control element, image display in which device functions on both sides are complementary to each other is realized.

According to the display device and the electronic apparatus of the embodiments of the present disclosure, the display section having the above-described first display panel and second display panel is provided, and therefore, image display on two display surfaces facing each other is realized by making device functions of the respective display panels complementary to each other. Therefore, user convenience can be improved. It should be noted that the effects described herein are not necessarily limiting and any other effects described in the present disclosure may be shown.

Drawings

Fig. 1A is a schematic plan view showing a configuration example of an electronic apparatus having a display device according to an embodiment of the present disclosure.

Fig. 1B is a schematic plan view showing a configuration example of the opposite side of the electronic apparatus shown in fig. 1A.

Fig. 2 is a block diagram schematically showing a schematic configuration example of the electronic apparatus shown in fig. 1A and 1B.

Fig. 3A is a schematic perspective view showing a schematic configuration example of the display section shown in fig. 2.

Fig. 3B is a schematic perspective view showing a schematic configuration example of the display section shown in fig. 3A viewed from the opposite side.

Fig. 4 is a schematic cross-sectional view showing a schematic configuration example of the pixel including the light emitting element shown in fig. 3A.

Fig. 5A is a schematic cross-sectional view showing an example of the action of the pixel shown in fig. 4.

Fig. 5B is a schematic cross-sectional view showing another example of the action of the pixel shown in fig. 4.

Fig. 6 is a schematic cross-sectional view showing a schematic configuration example of the pixel including the light control element shown in fig. 3B.

Fig. 7A is a schematic cross-sectional view showing an example of the action of the pixel shown in fig. 6.

Fig. 7B is a schematic cross-sectional view of another example of the action of the pixel shown in fig. 6.

Fig. 8A is a schematic plan view showing a state example of the standby operation.

Fig. 8B is a schematic plan view showing another state example of the standby operation.

Fig. 9A is a schematic cross-sectional view for describing the action of the state shown in fig. 8A.

Fig. 9B is a schematic cross-sectional view for describing the action of the state shown in fig. 8B.

Fig. 10A is a schematic plan view showing an example of a display manner when the background is set in a transparent state.

Fig. 10B is a schematic plan view showing another example of a display manner when the background is set in a transparent state.

Fig. 11A is a schematic cross-sectional view for describing an action of the display mode shown in fig. 10A.

Fig. 11B is a schematic cross-sectional view for describing the action of the display mode shown in fig. 10B.

Fig. 12A is a schematic cross-sectional view showing an action of an example of a display manner when a background is set in a monochrome reflective display state.

Fig. 12B is a schematic cross-sectional view of an action exemplified by another display manner when the background is set in a monochrome display state.

Fig. 13A is a schematic plan view for describing the display manner shown in fig. 12A.

Fig. 13B is a schematic plan view for describing the display manner shown in fig. 12B.

Fig. 14 is a schematic plan view showing an example of a display manner when the display surface is reversed.

Fig. 15 is a schematic plan view showing an example of a display mode of the case shown in fig. 14.

Fig. 16 is a schematic plan view showing another example of a display manner when the display surface is reversed.

Fig. 17 is a schematic plan view showing an example of a display mode of the case shown in fig. 16.

Fig. 18 is a diagram showing an example of an adaptive relationship between various indexes and each display mode.

Fig. 19 is a flowchart showing an example of display control according to the embodiment.

Fig. 20 is a flowchart showing an example of display control subsequent to fig. 19.

Fig. 21 is a flowchart showing another example of display control subsequent to fig. 19.

Fig. 22 is a flowchart showing a display control example subsequent to fig. 21.

Fig. 23 is a flowchart showing a display control example subsequent to fig. 22.

Fig. 24 is a flowchart showing another example of display control subsequent to fig. 20 and 22.

Fig. 25 is a schematic plan view showing a configuration example of an electronic apparatus with a display device according to modification 1.

Fig. 26A is a schematic plan view showing a state example of the electronic apparatus shown in fig. 25.

Fig. 26B is a schematic plan view showing an example of a display form of the electronic apparatus shown in fig. 25.

Fig. 26C is a schematic plan view showing another display form example of the electronic apparatus shown in fig. 25.

Fig. 27A is a schematic perspective view showing a configuration example of an electronic apparatus with a display device according to modification 2.

Fig. 27B is a schematic perspective view showing another configuration example of the electronic apparatus shown in fig. 27A.

Detailed Description

Embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. Note that description will be made in the following order.

1. Embodiment (example of application of display device to Mobile device used as example of electronic device)

2. Modification example

Modification 1 (example of foldable display)

Modification 2 (example of flexible display panels)

3. Other modifications

<1 > embodiment >

[ configuration example ]

Fig. 1A and 1B schematically show configuration examples of an electronic apparatus (electronic apparatus 1) having a display device according to an embodiment of the present disclosure in plan views (X-Y plan views), respectively. Specifically, fig. 1A shows a configuration example when viewed from a side provided with a display surface S1 (first display surface) which will be described later, and fig. 1B shows a configuration example when viewed from a side provided with a display surface S2 (second display surface) which will be described later (when viewed from a side opposite to the display surface S1).

In this example, the electronic apparatus 1 functions as, for example, a mobile apparatus (portable apparatus) such as a tablet terminal, a smartphone, and a mobile information terminal (PDA; personal digital assistant). The electronic apparatus 1 includes the display device according to the present embodiment in the casing 10, and the display device includes the display portion 11.

The display section 11 performs image display based on image signals (image signals Sv1 and Sv2 described below), and the display section 11 has display surfaces S1 and S2 (e.g., two display surfaces on the front side and the rear side) facing each other. The display section 11 has a plurality of pixels (

pixels

210 and 220 described below) including various display elements on the display surfaces S1 and S2. Further, the display portion 11 is configured to include components such as a driving device configured as various types of TFTs (thin film transistors) or the like in addition to these display elements. In this example, it is assumed that the display section 11 has an anisotropic shape (rectangular shape) in which the Y-axis direction (vertical direction) is the long axis direction and the X-axis direction (horizontal direction) is the short axis direction. It should be noted that this display section 11 is configured to include two types of display panels (display bodies), and detailed configuration examples thereof will be described later (fig. 2, fig. 3A, fig. 3B, and the like).

The case 10 is an exterior member that accommodates the display surfaces S1 and S2 in the display section 11, whereby the case 10 is visually recognizable. In this example, it is assumed that the housing 10 has an anisotropic shape (rectangular shape) in which the Y-axis direction is the long-axis direction and the X-axis direction is the short-axis direction. As shown in fig. 1A, the display surface S1 side (the frame region of the display unit 11) of the casing 10 is provided with

operation units

12a, 12b, and 12 c. As shown in fig. 1B, an illuminance sensor 14 is provided on the display surface S2 side (the frame region of the display unit 11) of the casing 10. Further, as shown in each of fig. 1A and 1B, the housing 10 has a center-of-gravity position sensor 13 built therein.

The

operation portions

12a, 12b, and 12c respectively function as parts (such as operation buttons) used when the user operates the electronic apparatus 1. It should be noted that, instead of providing the

operation sections

12a, 12b, and 12c, any type of various touch panels may be provided on the display section 11 (on the surface of each of the display surface S1 side and the display surface S2 side) so as to function as the operation section, thereby enabling the user to operate the electronic apparatus 1.

The center-of-gravity position sensor 13 is a sensor that detects the position of the center of gravity of the electronic apparatus 1 (for example, the posture of the electronic apparatus 1 such as information indicating which one of the surfaces of the casing 10 is facing upward). Examples of the center-of-gravity position sensor 13 include an acceleration sensor and a gyro sensor.

The illuminance sensor 14 is a sensor that detects an ambient illuminance (illuminance of external light entering through the periphery) corresponding to the brightness around the electronic apparatus 1. The illuminance sensor 14 is configured to include, for example, components such as various photodiodes having light receiving sensitivity in the visible light region.

[ schematic configuration example ]

Subsequently, a schematic configuration example of the electronic apparatus 1 (display device) will be described with reference to fig. 2, 3A, and 3B. Fig. 2 schematically shows a schematic configuration example of the electronic apparatus 1 in a block diagram. Fig. 3A schematically shows a schematic configuration example of the display section 11 in a perspective view, and fig. 3B schematically shows a schematic configuration example when the display section 11 shown in fig. 3A is viewed from the opposite side in a perspective view.

As shown in fig. 2, the electronic apparatus 1 includes a display control unit 15 that controls image display on the display unit 11, in addition to the

operation units

12a, 12b, and 12c, the center-of-gravity position sensor 13, and the illuminance sensor 14 of the display unit 11.

(display section 11)

As shown in fig. 2, the display section 11 is configured to cover (fix together) the

display panels

111 and 112 along the Z axis (thickness direction).

The display panel 111 (first display panel) is oppositely disposed on the display surface S1 side (in the positive direction of the Z axis), and is configured to output display light Ld1 to the front surface side (display surface S1 side) and the rear surface side (display surface S2 side) thereof. For example, as shown in fig. 3A, the display panel 111 has pixels 210 two-dimensionally arranged in a matrix on a display surface (X-Y plane) S1. The pixels 210 each include a light emitting element 211 which performs self-light emission. The light emitting element 211 is configured to emit light (display light Ld1) to the display surface S1 side and the display surface S2 side. In the display panel 111, since the light emitting element 211 is provided as a display element, although display of relatively high definition image quality is achieved, power consumption at the time of image display is relatively high as compared with the display panel 112 described below. Note that a detailed configuration example of this light emitting element 211 (fig. 4, fig. 5A, fig. 5B, and the like) will be described later.

The display panel 112 (second display panel) is oppositely disposed on the display surface S2 side (in the reverse direction of the Z axis), and is configured to output display light Ld2 to the front surface side (display surface S2 side) and the rear surface side (display surface S1 side) thereof. For example, as shown in fig. 3B, the display panel 112 has pixels 220 two-dimensionally arranged in a matrix on a display surface S2(X-Y plane). The pixels 220 each include a light control element 221, and the light control element 221 performs light control for controlling transmission and reflection of incident light (controlling switching between a transmission state and a reflection state). The light control element 221 also functions as a reflective display element, and the light control element 221 performs image display (reflected image display) using reflection of incident light. The light control element 221 is configured to perform such light control and reflection image display for the incident light entering from the display surface S1 side and the incident light entering from the display surface S2 side. In the display panel 112, since this light control element 221 is used as a display element, although power consumption at the time of image display is relatively low compared to the above-described display panel 111, image quality is also relatively low. Note that a detailed configuration example of this light control element 221 (fig. 6, 7A, 7B, and the like) will be described later.

(display control part 15)

The display control section 15 supplies an image signal (drive voltage) to the display section 11 on a pixel-by-pixel basis, thereby performing control (performing display control) that enables image display to be performed in the display section 11. Specifically, as described in detail below, in each of the

display panels

111 and 112 in the display section 11, the display control section 15 individually controls image display (performs individual control of image display). As shown in fig. 2, the display control section 15 has a control section 150 and two driving

sections

151 and 152.

The control section 150 controls the operation of each of the driving

sections

151 and 152 based on the image signals Sv1 and Sv2 input from the outside, the operation signal Sm supplied from the

operation sections

12a, 12b, 12c, the barycentric position signal Sg supplied from the barycentric position sensor 13, and the ambient illuminance Di supplied from the illuminance sensor 14. Here, the image signal Sv1 corresponds to an image signal for each pixel 210 in the display panel 111, and the image signal Sv2 corresponds to an image signal for each pixel 220 in the display panel 112. The operation signal Sm is a signal generated in accordance with an input operation performed by the user on the

operation portions

12a, 12b, and 12 c. The barycentric position signal Sg is a signal representing a detection result (such as posture information of the electronic apparatus 1) in the barycentric position sensor 13. The ambient illuminance Di corresponds to data representing the ambient illuminance detected in the illuminance sensor 14. Note that the control section 150 is configured using a microcomputer, for example.

The driving part 151 supplies a driving voltage Vd1 based on the image signal Sv1 to each pixel 210 in the display panel 111 according to the control of the control part 150. Similarly, the driving section 152 supplies a driving voltage Vd2 based on the image signal Sv2 to each pixel 220 in the display panel 112 according to the control of the control section 150. These driving

sections

151 and 152 are respectively configured using components such as semiconductor chips including various driving circuits (e.g., a scanning line driving circuit, a signal line driving circuit, and a power line driving circuit).

Here, as will be described in detail below, the light emission amount of each pixel 210 changes and the light reflection amount of each pixel 220 changes in the display panel 111 and the display panel 112 according to the driving voltage Vd1 applied to the light emitting element 211 and the driving voltage Vd2 applied to the light controlling element 221, respectively. Further, with such a change in the light emission amount and each of the light emission amounts, the light transmittance of each of the

pixels

210 and 220 changes. However, the correspondence between the application of the presence/absence of the driving voltages Vd1 and Vd2 (voltage amplitudes) and the presence/absence of the light transmittance is not limited to the correspondence described below, and may be other correspondences (e.g., inverse correspondences).

[ Cross-sectional configuration example ]

Subsequently, a cross-sectional configuration example (pixels 210 and 220) of each of the

display panels

111 and 112 will be described with reference to fig. 4, 5A, 5B, 6, 7A, and 7B.

(display panel 111)

Fig. 4 schematically shows a schematic configuration example (pixel 210) of the display panel 111 in a cross-sectional view. The pixels 210 in the display panel 111 are each configured to include a light emitting element 211, and in this example, the light emitting element 211 is configured as an organic electroluminescence (electroluminescence) device (organic electroluminescence element).

In this example, the display panel 111 is configured to perform color image display by using a configuration based on a top surface light emitting system (so-called top emission system) by outputting display light Ld1 to the above-described display surface S1 side and display surface S2 side. In other words, the pixels 210 are each configured to emit display light Ld1 corresponding to, for example, any one of red (R), green (G), and B (blue) among the three primary colors.

The light emitting element 211 (organic EL device) in each pixel 210 is sealed on the drive substrate 30 by a sealing substrate 37. In each light emitting element 211, an inter-pixel insulating film 32, an organic layer 33, and a second electrode (upper electrode) 34 are laminated in this order on a first electrode (lower electrode) 31. In the display panel 111, a protective film 35 is formed to cover each light emitting element 211, and on this protective film 35, a sealing substrate 37 is laminated with a black matrix 36 interposed therebetween. The organic layer 33 includes layers such as a hole injection layer, a hole transmission layer, a light emitting layer, and an electron transmission layer, which are not shown. Among these layers, the light emitting layer is a layer that emits different color light of each pixel 210 corresponding to the above-described three primary colors (red light emitting layer, green light emitting layer, or blue light emitting layer), and for each of these pixels 210, the light emitting layer is colored so as to form a predetermined pattern. Further, in the region between the pixels 210 on the protective film 35, the black matrix 36 is provided.

It is to be noted that, for example, for the purpose of improvement in contrast such as at the time of image display, color filters corresponding to the above-mentioned three primary colors may be provided on at least one of the display surface S1 side (upper portion) and the display surface S2 side (lower portion) of the light emitting element 211. Further, in this example, the display panel 111 is configured based on a top surface light emitting system, but is not limited to this system, and may be configured based on, for example, a bottom surface light emitting system (so-called lower emission system).

Here, in the display panel 111, each layer is configured using a light-transmitting material (transparent material) so that at least a part thereof exhibits light transmittance (transparency) in each of the layers. Specifically, the drive substrate 30 and the sealing substrate 37 are each configured using, for example, a substrate such as a glass substrate and a light-transmitting resin substrate. In addition, the first electrode 31, the second electrode 34, and components such as electrodes and wirings in each device on the drive substrate 30 are each made of, for example, a transparent oxide semiconductor such as ITO, IZO (indium tin oxide), and AZO (zinc aluminum oxide), or a light-transmitting material such as transparent carbon. The layers such as the organic layer 33 and the protective film 35 are also each made of different light-transmitting materials.

In the display panel 111 having such a configuration, the light emission amount of each pixel 210 changes according to the driving voltage Vd1 applied to each light emitting element 211. Further, the light transmission amount also changes with such a change in the light emission amount, and therefore, the light transmittance of each pixel 210 changes.

Specifically, for example, as shown in fig. 5A, when the driving voltage Vd1 is not applied to the light emitting element 211 in the pixel 210 (or the voltage value thereof is small), the external light Le entering from the display surface S1 side and the external light Le entering from the display surface S2 side pass through the pixel 210. In other words, at this time, the corresponding pixel 210 in the display panel 111 exhibits light transmittance (transparency), and is thus in a transparent state.

On the other hand, for example, as shown in fig. 5B, when the driving voltage Vd1 is applied to the light emitting element 211 in the pixel 210 (or the voltage value thereof is large), emitted light (display light Ld1) is output from the above-described light emitting element 211 to the display surface S1 side and the display surface S2 side. In other words, at this time, the corresponding pixel 210 in the display panel 111 does not exhibit light transmittance, and is therefore in a non-transparent state (a display state based on the display light Ld 1).

(display panel 112)

Fig. 6 schematically shows a schematic configuration example (pixel 220) of the display panel 112 in a cross-sectional view. In this example, the pixels 220 in the display panel 112 are each configured to include a light control element 221, and the light control element 221 is configured by a liquid crystal device including cholesteric liquid crystal.

The display panel 112 also performs color image display as with the display panel 111. In other words, the pixels 220 are each configured to output display light Ld2 corresponding to any one of red (R), green (G), and B (blue) among the three primary colors, for example.

In this display panel 112, between the drive substrate 40 and the transparent substrate 45, the pixel electrode 41, the liquid crystal layer 42, the common electrode 43, and the black matrix 44M or the color filter 44C are provided in this order from the drive substrate 40 side. A color filter 44C is arranged for each pixel 220, and a black matrix 44M is arranged in the region between the pixels 220. The liquid crystal layer 42 is configured by cholesteric liquid crystal. Of these, the pixel electrode 41, the liquid crystal layer 42, and the common electrode 43 are used to dispose the light control element 221 (liquid crystal device).

Here, in the display panel 112, like the display panel 111, each layer is configured using a light-transmitting material (transparent material) so that at least a part thereof exhibits light-transmitting properties in each of the layers. Specifically, the drive substrate 40 and the transparent substrate 45 are each configured using, for example, substrates such as a glass substrate and a light-transmitting resin substrate. Further, for example, the pixel electrode 41, the common electrode 43, and components such as electrodes and wirings of each device on the driving substrate 40 are each made of, for example, a transparent oxide semiconductor such as ITO, IZO, and AZO, or a light-transmitting material such as transparent carbon.

In the display panel 112 (pixels 220) having such a configuration, the amount of light reflection in each pixel 220 is changed according to the driving voltage Vd2 applied to each light control element 221. Further, as with the display panel 111, the light transmission amount also changes with such a change in the light emission amount, and therefore, the light transmittance of each pixel 220 changes.

Specifically, for example, as shown in fig. 7A, when the driving voltage Vd2 is not applied to the light control element 221 in the pixel 220 (or the voltage value thereof is small), the external light Le entering from the display surface S1 side and the external light Le entering from the display surface S2 side pass through the pixel 220. In other words, at this time, the corresponding pixel 220 in the display panel 112 exhibits light transmittance (transparency), and is thus in a transparent state.

On the other hand, for example, as shown in fig. 7B, when the driving voltage Vd2 is applied to the light control element 221 in the pixel 220 (or the voltage value thereof is large), the following occurs. That is, in the pixel 220 (light control element 221), light control for causing reflection is performed for the above-described incident light (such as the external light Le) entering from the display surface S1 side and the incident light (such as the external light Le) entering from the display surface S2 side. Therefore, the display light Ld2 based on the incident light is output to the display surface S1 side and the display surface S2 side so that the reflected image display is performed. In other words, at this time, the corresponding pixel 220 in the display panel 112 does not exhibit light transmittance, and is therefore in a non-transparent state (a display state based on the display light Ld 2).

[ actions and effects ]

(A. basic operation)

For example, as shown in fig. 2, in this electronic apparatus 1 (display device), the image signals Sv1 and Sv2 for the

display panels

111 and 112 are respectively supplied to the control section 150 in the display control section 15. Further, the operation signal Sm from the

operation units

12a, 12b, and 12c, the center-of-gravity position signal Sg from the center-of-gravity position sensor 13, and the ambient illuminance Di from the illuminance sensor 14 are supplied to the control unit 150, respectively. The control section 150 controls the operation of each of the

drive sections

151 and 152 based on the image signals Sv1 and Sv2, the operation signal Sm, the center-of-gravity position signal Sg, and the ambient illuminance Di. The driving

sections

151 and 152 supply driving voltages Vd1 and Vd2 based on the image signals Sv1 and Sv2 to the

pixels

210 and 220 in the

display panels

111 and 112, respectively, according to the control of the control section 150.

In this way, the image display of each of the

display panels

111 and 112 is individually controlled by the display control section 15 (individual control of image display is performed). Further, the display panel 111 is oppositely disposed on the display surface S1 side, and outputs display light Ld1 to the display surface S1 side and the display surface S2 side. Further, the display panel 112 is oppositely disposed on the display surface S2 side, and outputs display light Ld2 to the display surface S1 side and the display surface S2 side. Therefore, in this electronic apparatus 1 (display device), by using these two types of

display panels

111 and 112, image display (double-sided display) is realized on the display surfaces S1 and S2 facing each other.

(B. summary of actions for each operation)

Subsequently, an outline of an action in each operation (standby operation and image display operation) of the electronic apparatus 1 (display device) will be described with reference to diagrams including fig. 8A to 13B.

(Standby operation)

First, for example, as shown in fig. 8A and 8B, in a standby operation (in a standby state) of the electronic apparatus 1, display control is performed so that pixel regions (regions where the

pixels

210 and 220 are arranged) in the

respective display panels

111 and 112 are both in a transparent state. In other words, the display control section 15 performs display control such that when it is detected that the electronic apparatus 1 is in the standby state based on a signal such as the operation signal Sm, the pixel regions in the

respective display panels

111 and 112 are both in the transparent state.

It should be noted that the example shown in fig. 8A represents a state in which the user holds the electronic apparatus 1 in the standby state with the hand h so that the display surface S1 faces upward. Further, the example shown in fig. 8B represents a state in which the user holds the electronic apparatus 1 in a standby state with the hand h so that the display surface S2 faces upward.

Here, in the example of each of fig. 8A and 8B, the display control section 15 supplies neither the driving voltage Vd1 nor the driving voltage Vd2 to the

pixels

210 and 220 in the

display panel

111 and 112, for example, as shown in fig. 9A and 9B. Therefore, in each of the

display panels

111 and 112, the external light Le entering from the display surface S1 side and the external light Le entering from the display surface S2 side pass through each of the

pixels

210 and 220 described above. Accordingly, all the

pixels

210 and 220 in the

display panels

111 and 112 exhibit light transmittance, and thus are in a transparent state as illustrated in fig. 8A and 8B.

In this way, in the standby state of the electronic apparatus 1 (display device), the display section 11 is in the transparent state (transparent panel) when viewed from the display surface S1 side or from the display surface S2 side. Thus, a display design with an improved brightness impression can be achieved.

(in the image display operation: the background is in a transparent state)

Subsequently, for example, as shown in fig. 10A and 10B, in the image display operation of the electronic apparatus 1, there are the following cases as a first example: a part of the display portion 11 displays an image while a background portion of the image is in a transparent state. In other words, when an instruction for setting such a display mode is set, the display control section 15 performs display control in the

display panels

111 and 112 so as to allow such a partial image display state and a transparent state.

It should be noted that the example shown in fig. 10A represents a state in which the user holds the electronic apparatus 1 with the hand h so that the display surface S1 faces upward while an image (letter "a") is displayed on a part of the display surface S1 of the electronic apparatus 1. Further, the example shown in fig. 10B represents a state in which the user holds the electronic apparatus 1 with the hand h so that the display surface S2 faces upward while an image (letter "B") is displayed on a part of the display surface S2 of the electronic apparatus 1.

At this time, in the example of fig. 10A, the display control section 15 executes the following display control in the display panel 111, for example, as shown in fig. 11A. That is, the driving voltage Vd1 is supplied to the pixels 210 in the display pixel region, whereas the driving voltage Vd1 is not supplied to the pixels 210 in the background region (non-display pixel region). On the other hand, in this first example, the display control section 15 does not supply the driving voltage Vd2 to all the pixels 220 in the display panel 112. Therefore, in the display pixel region of the display panel 111, emitted light (display light Ld1) is output from the light emitting element 211 to the display surface S1 side and the display surface S2 side as described above, and thus a non-transparent state is created. Meanwhile, in the background region of the display panel 111, the outside light Le entering from the display surface S1 side and the outside light Le entering from the display surface S2 side as described above pass therethrough, and thus a transparent state is created. On the other hand, in the display panel 112, the external light Le entering from the display surface S1 side and the external light Le entering from the display surface S2 side as described above pass through all the pixels 220, and thus a transparent state is created. In this way, as shown in fig. 10A, when the display surface S1 faces upward, the partial image display state and the transparent state of the display section 11 are realized. Note that, in this case, the display light Ld1 is output to the display surfaces S1 and S2, and therefore, the image display (letter "a") is visually recognizable not only from the display surface S1 side (upper side) but also from the display surface S2 side (lower side).

On the other hand, in the example of fig. 10B, the display control section 15 performs the following display control in the display panel 112, for example, as shown in fig. 11B. That is, the driving voltage Vd2 is supplied to the pixels 220 in the display pixel region, whereas the driving voltage Vd2 is not supplied to the pixels 220 in the background region (non-display pixel region). On the other hand, in this first example, the display control section 15 does not supply the driving voltage Vd1 to all the pixels 210 in the display panel 111. Therefore, in the display pixel region of the display panel 112, for incident light (such as the external light Le) entering from the display surface S1 side and the S2 side, the display light Ld2 based on the incident light is output to the display surface S1 side and the display surface S2 side as described above, and reflection image display is performed. In other words, the display pixel region 210 is in a non-transparent state because the incident light is reflected. Meanwhile, in the background region of the display panel 112, the outside light Le entering from the display surface S1 side and the outside light Le entering from the display surface S2 side as described above pass therethrough, and thus a transparent state is created. On the other hand, in the display panel 111, in all the pixels 210, the external light Le entering from the display surface S1 side and the external light Le entering from the display surface S2 side as described above pass therethrough, and thus the transparent state is created. In this way, when the display surface S2 faces upward, as shown in fig. 10B, the partial image display state and the transparent state of the display section 11 are realized. Note that, also in this case, the display light Ld2 is output to the display surfaces S1 and S2, and therefore, the image display (letter "B") is visually recognizable not only from the display surface S2 side (upper side) but also from the display surface S1 side (lower side).

In this way, in the first example of the image display operation of the electronic apparatus 1 (display device), as in the above-described standby state, when viewed from the display surface S1 side or the display surface S2 side, the display section 11 is in a transparent state in its background portion while the display section 11 partially displays an image. Thus, the necessary image display can be performed while maintaining the improved brightness impression to a certain extent.

However, in this first example, the following disadvantages may occur according to circumstances, and thus user convenience may be reduced.

Specifically, in the example shown in fig. 10A and 11A (the example in which the display surface S1 faces upward), display light Ld1 is emitted from the light emitting element 211 in the display pixel region toward the display surfaces S1 and S2 as described above, and display light Ld1 emitted toward the display surface S2 side passes through the display panel 112. Therefore, when the display image is viewed from the side of the display surface S1 (or the side of the display surface S2), the display illuminance in that direction (side) is relatively a half (1/2) value, and therefore, the contrast ratio may decrease, which may cause deterioration in the display image quality.

On the other hand, in the example shown in fig. 10B and 11B (the example in which the display surface S2 faces upward), as described above, the reflected image display based on the incident light such as the external light Le is performed in the light control element 221 of the display pixel region. In this case, in a dark environment where the outside light Le is small (in the case where the ambient illuminance is low), the display image is not easily visible (or hardly visible).

(in the image display operation: the background is in the monochrome reflection display state or the monochrome display state)

Therefore, in the image display operation of the electronic apparatus 1, there are the following cases as a second example: the display control section 15 performs display control as shown in fig. 12A and 12B, for example.

It should be noted that, as with the example of fig. 10A and 11A, the example shown in fig. 12A represents a state in which the display surface S1 faces upward, and an image (letter "a") portion is displayed on this display surface S1. Further, as with the example in fig. 10B and 11B, the example shown in fig. 12B represents a state in which the display surface S2 faces upward, and an image (letter "B") portion is displayed on this display surface S2.

Here, in the example of fig. 12A, the display control section 15 performs display control in the display panel 111, which is similar to the display control in the first example (the examples in fig. 10A and 11A). In other words, the driving voltage Vd1 is supplied to the pixels 210 in the display pixel region, however, the driving voltage Vd1 is not supplied to the pixels 210 in the background region. However, in the second example, unlike the first example, the display control section 15 supplies the same (common) drive voltage Vd2 to all the pixels 220 in the display panel 112. Accordingly, the entire pixel area of the display panel 112 is in a monochrome reflective display state (for example, a full white display state) based on the reflective image display. Therefore, the display light Ld1 emitted from the light emitting element 211 of the display pixel region toward the display surface S2 side is reflected by the light control element 221 in the display panel 112, and is finally output toward the display surface S1 side. In other words, by utilizing light control (light reflection) by the light control element 221 in the display panel 112, an effect of contrast enhancement (supplementation) of image display in the display panel 111 (an effect of improving the utilization rate of the display light Ld1) can be obtained.

Therefore, for example, as shown in fig. 13A, in this second example, when the display image is viewed from the display surface S1 side, the contrast reduction accompanying the reduction in display illuminance is reduced or avoided, and the display image quality is improved (user convenience improvement) as compared with the first example. Note that in this example of fig. 13A, since the entire pixel region of the display panel 112 is in the monochrome reflective display state, the background portion in the display section 11 is also in the monochrome reflective display state (non-transparent state) unlike the first example shown in fig. 11A.

On the other hand, in the example of fig. 12B, the display control section 15 performs display control in the display panel 112, which is similar to the display control in the first example (the examples in fig. 10B and 11B). In other words, the driving voltage Vd2 is supplied to the pixels 220 in the display pixel region, whereas the driving voltage Vd2 is not supplied to the pixels 220 in the background region. However, in this second example, unlike the first example, the display control section 15 supplies the same (common) drive voltage Vd1 to all the pixels 210 in the display panel 111. Therefore, the entire pixel region in the display panel 111 is in a monochrome display state (for example, a full white display state or a specific color display state) based on light emission of the light emitting element 211. In other words, the display light Ld1 output from the display panel 111 (to the display surface S1 side) can be utilized complementarily in the image display of the display panel 112, so that the display panel 111 functions as an auxiliary light source (backlight).

Therefore, in this second example, unlike the first example, for example, as shown in fig. 13B, when the display image is viewed from the display surface S2 side, the display image is easily viewed even in a dark environment where the external light Le is less (a case where the ambient illuminance is low) (user convenience improvement). Note that, also in this example of fig. 13B, since the entire pixel region of the display panel 111 is in a monochrome display state, the background portion in the display section 11 is also in a monochrome display state (non-transparent state) unlike the first example shown in fig. 11B.

In this way, when the second example is used for image display, the functions (device functions) of the light emitting elements 211 in the display panel 111 and the functions of the light control elements 221 in the display panel 112 are complementary to each other, thereby realizing image display (double-sided display) on the display surfaces S1 and S2. Therefore, improvement in user convenience can be expected.

(C. multiple display modes)

Subsequently, a plurality of types (in this example, six types) of display modes set in the electronic apparatus 1 (display device) will be described with reference to drawings including fig. 14 to 18. In other words, the display control section 15 performs individual control of image display in each of the

display panels

111 and 112 so as to perform one display mode selected from a plurality of display modes with a change in light transmittance of each of the

pixels

210 and 220 described above.

It should be noted that the display mode may be arbitrarily set (selected, or switched) according to, for example, power saving, ambient lighting environment, screen design or image quality preference (selectivity), image type, or the like, as will be described later in detail. Further, as for the method of making such a selection, only one or a combination of manual selection (manual control) using an input operation performed by the user on the

operation sections

12a, 12b, and 12c and automatic selection (automatic control) using information such as a detection result in the illuminance sensor 14 as described below may be utilized.

(first to third display modes: display surface S1 faces upward)

First, three display modes (first to third display modes) among the above-described six display modes will be described with reference to the drawings including fig. 14 and 15. As will be described below, these first to third display modes are each set as a display mode set when it is detected that the display surface S1 faces upward.

Here, description will be provided using a case where the electronic apparatus 1 (display device) is inverted (turned upside down) as an example, the electronic apparatus 1 is inverted by changing from a state in which the display surface S2 faces upward as shown in part (a) of fig. 14, for example, to a state in which the display surface S1 faces upward as shown in part (B) of fig. 14, for example (see arrow P11 in fig. 14).

In this case, when it is determined by the barycentric position signal Sg obtained in the barycentric position sensor 13 that a change from the state in which the display surface S2 faces upward to the state in which the display surface S1 faces upward occurs, the display control section 15 performs the following display control. That is, the control switches the image display from a state in which an image is displayed in the display panel 112 on the side of the display surface S2 (in this example, a partial display in which the letter "B" is displayed) as shown in, for example, part (a) of fig. 14 to a state in which the same image is displayed in the display panel 111 on the side of the display surface S1 as shown in, for example, part (B) of fig. 14.

Note that at this time, for example, as shown by, for example, reference numeral P12 in part (B) of fig. 14, the following information may be temporarily displayed on the display section 11 (display surface S1). That is, for example, since the image display state in the display panel 112 is switched to the image display state in the display panel 111, information indicating "power consumption increase" or "high-definition image quality mode start" can be temporarily displayed. Further, index information of power consumption in the selected display mode (for example, information such as the duration of a built-in battery in the electronic apparatus 1) may be displayed on the display portion 11 (display surface S1). When such information is displayed, useful information is provided to the user, and therefore, further improvement in user convenience can be expected.

Further, when image display by the light emitting element 211 is thus performed in at least a part of the pixel region in the display panel 111 on the display surface S1 side (the display light Ld1 is output to the display surface S1 side and the display surface S2 side), the display control section 15 performs the following display control. That is, individual control of image display of each of the

display panels

111 and 112 is performed so as to perform (set) one display mode selected from first to third display modes described below.

Here, when the first display mode is set, the image is displayed as shown in part (a) of fig. 15, for example. Specifically, in the display panel 111 on the side of the display surface S1 (front side), the display control section 15 performs display control so as to perform image display by utilizing the emission state by the light emitting elements 211 as described above. On the other hand, in the display panel 112 on the side of the display surface S2 (rear side), the display control section 15 performs display control so as to put the entire pixel area of the display panel 112 in a transparent state (light transmission state) by utilizing transmission of incident light such as the external light Le by the light control element 221. In other words, this first display mode corresponds to the example (first example of image display) in fig. 10A and 11A described above.

In this first display mode, when viewed from the display surface S1 side or the display surface S2 side as described above, the display section 11 is in a transparent state in its background portion while the display section 11 (display surface S1) partially displays an image. Thus, the necessary image display can be performed while maintaining the improved brightness impression to a certain extent.

Further, when the second display mode is set, the image is displayed as shown in part (B) of fig. 15, for example. Specifically, with respect to the display panel 111 on the side of the display surface S1, the display control section 15 performs display control in a manner similar to the display control in the first display mode. On the other hand, in the display panel 112 on the display surface S2 side, the display control section 15 performs display control so as to put the entire pixel region of the display panel 112 in a monochrome reflection display state by utilizing reflection image display based on incident light (such as the display light Ld1, and the external light Le) by the light control element 221. In other words, this second display mode corresponds to the example (the second example in image display) in fig. 12A and 13A described above.

In this second display mode, as described above, when the display image is viewed from the display surface S1 side, the reduction in contrast accompanying the reduction in display illuminance is reduced or avoided, and therefore, compared with the first display mode, the display image quality improves, thereby improving user convenience.

When the third display mode is set, the image is displayed as shown in part (C) of fig. 15, for example. Specifically, with respect to the display panel 111 on the side of the display surface S1, the display control section 15 performs display control in a manner similar to the display control of each of the first and second modes. On the other hand, in the display panel 112 on the display surface S2 side, display control is performed so as to create a partially monochrome reflective display state and a transparent state. Specifically, based on a principle similar to the second display mode, display control is performed such that the vicinity of the pixel region corresponding to (facing) the display pixel region in the display panel 111 is in a monochrome reflective display state. Further, based on a principle similar to the first display mode, display control is performed so that the vicinity of the non-display pixel region (transparent pixel region or background region) of the display panel 111 is in a transparent state. In other words, in this third display mode, the partial monochrome reflective display in the display panel 112 on the rear side is performed by creating an association with the display image in the display panel 111 on the front side.

In this third display mode, first, as in the first display mode, although the display section 11 (display surface S1) partially displays an image, the display section 11 is in a transparent state in its background portion when viewed from the display surface S1 side or the display surface S2 side. Further, in the display pixel region, image display by selective addition of the

display panels

111 and 112 is performed, and therefore, an effect of contrast improvement is selectively obtained in the display pixel region based on a principle similar to the second display mode. Thus, the advantages of the first and second display modes can be achieved, which makes it possible to perform the necessary image display of high definition image quality while maintaining the advanced brightness impression to a certain extent. Therefore, in this third display mode, further improvement in user convenience can be expected.

Here, for example, selection of one display mode from among the first to third display modes is set in accordance with the operation signal Sm obtained by performing an input operation on the

operation portions

12a, 12b, and 12c as described above. Further, other settings such as color settings in the monochrome reflective display state in the display panel 112 in the second and third display modes (for example, arbitrary colors other than the above-described white color, such as red, green, and blue) and settings of portions of the pixel region in the monochrome reflective display state or the transparent state in the third display mode can also be arbitrarily adjusted (set) in accordance with the operation signal Sm. In this case, such settings may be arbitrarily adjusted according to user preferences or use environments, and therefore, further improvement in user convenience may be expected.

In this way, in the electronic apparatus 1, when it is detected that the display surface S1 faces upward, any one of the first to third display modes is arbitrarily set according to, for example, various indices described later, and therefore, further improvement in user convenience can be expected.

(fourth to sixth display modes: display surface S2 faces upward)

Subsequently, the remaining three display modes (fourth to sixth display modes) of the above-described six display modes will be described with reference to the drawings including fig. 16 and 17. As will be described below, these fourth to sixth display modes are each set as a display mode set when it is detected that the display surface S2 faces upward.

Here, description will be provided using a case where the electronic apparatus 1 (display device) is inverted (turned upside down) as an example, the electronic apparatus 1 is inverted by changing from a state in which the display surface S1 faces upward as shown in part (a) of fig. 16, for example, to a state in which the display surface S2 faces upward as shown in part (B) of fig. 16, for example (see arrow P21 in fig. 16).

In this case, when it is determined by the barycentric position signal Sg obtained in the barycentric position sensor 13 that a change from the state in which the display surface S1 faces upward to the state in which the display surface S2 faces upward occurs, the display control section 15 performs the following display control. That is, the control switches the image display from a state in which an image is displayed in the display panel 111 on the side of the display surface S1 (in this example, a partial display in which the letter "a" is displayed) as shown in, for example, part (a) of fig. 16 to a state in which the same image is displayed in the display panel 112 on the side of the display surface S2 as shown in, for example, part (B) of fig. 16.

Note that at this time, for example, as shown by, for example, reference numeral P22 in part (B) of fig. 16, the following information may be temporarily displayed on the display section 11 (display surface S2). That is, for example, since the image display state in the display panel 111 is switched to the image display state in the display panel 112, information indicating "power consumption reduction" or "transfer mode (carry mode) start" may be temporarily displayed. Further, also in this case, as described above, the index information of power consumption in the selected display mode may be displayed on the display portion 11 (the display surface S2). Further, in this case, the index value of the ambient brightness Di detected by the illuminance sensor 14 may be displayed on the display section 11 (display surface S2). When such information is displayed, useful information is provided to the user, and therefore, further improvement in user convenience can be expected.

Further, when the reflected image display by the light control element 221 (the display light Ld2 is output to the display surface S1 side and the S2 side) is thus performed in at least a part of the pixel region in the display panel 112 on the display surface S2 side, the display control section 15 performs the following display control. That is, individual control of image display of each of the

display panels

111 and 112 is performed so as to perform (set) one display mode selected from fourth to sixth display modes described below.

Here, when the fourth display mode is set, the image is displayed as shown in part (a) of fig. 17, for example. Specifically, in the display panel 112 on the side (front side) of the display surface S2, the display control section 15 performs display control so as to perform reflection image display (change to a light reflection state) by reflection of incident light such as the external light Le by the light control element 221 as described above. On the other hand, in the display panel 111 on the side of the display surface S1 (rear side), the display control section 15 performs display control so that the entire pixel region of the display panel 111 is in a transparent state (light transmitting state) by the light emitting element 211 with a non-emission state (extinction state). In other words, this fourth display mode corresponds to the example (first example of image display) in fig. 10B and 11B described above.

In this fourth display mode, although the display section 11 (display surface S2) partially displays an image, the display section 11 is in a transparent state in its background portion when viewed from the display surface S1 side or the display surface S2 side as described above. Thus, the necessary image display can be performed while maintaining the improved brightness impression to a certain extent.

Further, when the fifth display mode is set, an image is displayed as illustrated in part (B) of fig. 17, for example. Specifically, with respect to the display panel 112 on the side of the display surface S2, the display control section 15 performs display control in a manner similar to the display control in the fourth display mode. On the other hand, in the display panel 111 on the side of the display surface S1, the display control section 15 performs display control so that the entire pixel area of the display panel 111 is in a monochrome display state by utilizing the emission state (light irradiation state) by the light emitting element 211. In other words, this fifth display mode corresponds to the example (the second example in image display) in fig. 12B and 13B described above.

In this fifth display mode, as described above, the display panel 111 serves as an auxiliary light source. Therefore, unlike the fourth display mode, when the display image is viewed from the display surface S2 side, the display image is easily viewed even in a dark environment where the external light Le is less, and therefore, the user convenience improves. Further, it is possible to realize effects such as that the display image viewed from the display surface S2 side and the display image viewed from the display surface S1 side are different from each other in terms of image perception.

When the sixth display mode is set, the image is displayed as shown in part (C) of fig. 17, for example. Specifically, with respect to the display panel 112 on the side of the display surface S2, the display control section 15 performs display control in a manner similar to the display control of each of the fourth and fifth modes. On the other hand, in the display panel 111 on the side of the display surface S1, display control is performed so as to create a partially monochrome display state and a transparent state. Specifically, based on a principle similar to the fifth display mode, display control is performed so that the vicinity of a pixel region corresponding to (facing) a display pixel region in the display panel 112 is in a monochrome display state. Further, based on a principle similar to the fourth display mode, display control is performed so that the vicinity of the non-display pixel region (transparent pixel region or background region) of the display panel 112 is in a transparent state. In other words, in this sixth display mode, partial monochrome display in the display panel 111 on the rear side is performed by creating an association with a display image in the display panel 112 on the front side.

In this sixth display mode, first, as in the fourth display mode, although the display section 11 (display surface S2) partially displays an image, the display section 11 is in a transparent state in its background portion when viewed from the display surface S1 side or the display surface S2 side. Further, as in the fifth display mode, when the display image is viewed from the display surface S2 side, the display image is easily viewed even in a dark environment where the external light Le is less. Further, in this display pixel region, image display by selective addition of the

display panels

111 and 112 is performed, and therefore, an effect of contrast improvement can also be expected. Therefore, the advantages of the fourth and fifth display modes, and the like, which make it possible to perform necessary image display of high-definition image quality even in a dark environment while maintaining the advanced luminance impression to some extent, can be achieved. Therefore, in this sixth display mode, further improvement in user convenience can be expected.

Here, for example, selection of one display mode from among the fourth to sixth display modes is set in accordance with the operation signal Sm obtained by performing an input operation on the

operation portions

12a, 12b, and 12c as described above, or the ambient brightness Di detected by the illuminance sensor 14. Further, other settings such as color settings (for example, white, red, green, and blue) in the monochrome display state in the display panel 111 in the fifth and sixth display modes and settings of the portion of the pixel region in the monochrome display state or the transparent state in the sixth display mode can also be arbitrarily adjusted (set) in accordance with the operation signal Sm. In this case, such settings may be arbitrarily adjusted according to user preferences or use environments, and therefore, further improvement in user convenience may be expected.

In this way, in the electronic apparatus 1, when it is detected that the display surface S2 faces upward, any one of the fourth to sixth display modes may be arbitrarily set according to various indices such as those described later, and therefore, further improvement in user convenience may be expected.

(adaptive relationship between various indexes and each display mode)

Here, part (a) to part (D) of fig. 18 schematically show examples of the adaptive relationship between various indexes and each display mode. It should be noted that each of the metrics described herein is merely an example, and other metrics may be utilized when selecting a display mode.

First, part (a) of fig. 18 shows an example corresponding to each display mode with respect to adaptability to presence/absence of an external power supply (power saving) of the electronic apparatus 1. It should be noted that in this example, each of the cases of use in a house (presence of external power) and use in a garden or train (absence of external power, and use of battery drive) is shown by being associated with the assumption of an appropriate display mode.

As shown in part (a) of fig. 18, it can be said that when there is an external power supply, it is desirable to perform image display with priority for image quality by using display modes (first to third display modes) that allow visual recognition of the display surface S1 (the display panel 111 including the light-emitting element 211) facing upward. On the other hand, when there is no external power supply (battery-driven), it can be said that it is desirable to perform image display with priority for power saving and priority for movement by using display modes (fourth to sixth display modes) that allow visual recognition of the upward facing display surface S2 (the display panel 112 including the light control element 221). Therefore, by setting the display mode, image display suitable for the presence/absence of the external power supply (power saving) can be realized.

Further, part (B) of fig. 18 shows an example corresponding to each display mode with respect to adaptability to the ambient light environment when the electronic apparatus 1 is used. It should be noted that in this example, each case of use at night (when the ambient illuminance is low) and use in the daytime or in the indoor of direct sunlight (when the ambient illuminance is high) is shown by being associated with the assumed appropriate display mode.

As shown in this part (B) of fig. 18, when the ambient illuminance is low (in a dark-light environment), it can be said that it is desirable to perform image display based on self-luminescence by using display modes (first to third display modes) that allow visual recognition that the display surface S1 (the display panel 111 including the light-emitting element 211) faces upward. On the other hand, when the ambient illuminance is high (in a bright lighting environment), it can be said that it is desirable to perform reflection image display by using the display modes (fourth to sixth display modes) that allow visual recognition of the upward facing display surface S2 (the display panel 112 including the light control element 221). Therefore, by setting the display mode, image display suitable for the ambient lighting environment can be realized.

Part (C) of fig. 18 shows an example corresponding to each display mode with respect to adaptability to unique design and unique performance preference (mode) in the electronic apparatus 1 (display section 11). It should be noted that in this example, each of the normal manner, the unique emphasis manner, and the flare effect expression manner is shown by being associated with the assumed appropriate display mode.

As shown in part (C) of fig. 18, it can be said that the second and fifth display modes in which the background portion is in the monochrome reflection display state or the monochrome display state are relatively normal display modes. Meanwhile, it can be said that the fourth and sixth display modes in which the reflected image display is performed with the background portion substantially in the transparent state are relatively unique display modes. Further, it can be said that the first and third display modes in which the self-luminous-based image display is performed with the background portion substantially in the transparent state are the blaze effect expression display modes. Therefore, by setting the display mode, image display suitable for various modes can be realized.

Part (D) of fig. 18 shows an example corresponding to each display mode in terms of adaptability to the type of image displayed in the electronic apparatus 1 (display section 11). It should be noted that in this example, each of the case of an image for picture appreciation (still image), the case of an image for movie (moving image that is not moving so fast), and the case of a moving image (moving image that is moving fast) is shown by being associated with the assumption of an appropriate display mode.

As shown in part (D) of fig. 18, in the case of moving an image, it can be said that it is desirable to perform image display based on self-luminescence by using display modes (first to third display modes) that allow visual recognition of the display surface S1 (the display panel 111 including the light emitting element 211) facing upward. On the other hand, in the case of a still image, it can be said that it is desirable to perform reflection image display by using display modes (fourth to sixth display modes) that allow visual recognition of the upward facing display surface S2 (the display panel 112 including the light control element 221). Therefore, by setting the display mode, image display suitable for the type of display image can be realized.

(D. concrete example of display control)

Subsequently, a specific example of display control in the electronic apparatus 1 (an example of a series of steps in display control performed after the power of the electronic apparatus 1 enters the on state and before the power enters the off state) will be described with reference to fig. 19 to 24.

Fig. 19 to 24 show in flowcharts an example of a series of steps of display control by the display control section 15 (mainly, the control section 150).

When the power supply of the electronic apparatus 1 enters the ON (ON) state, first, the display control unit 15 acquires the center-of-gravity position signal Sg from the center-of-gravity position sensor 13 (step S101 in fig. 19). Subsequently, based on the barycentric position signal Sg, the display control section 15 determines whether the display surface S1 is in the upward facing state (step S102). Here, when it is determined that the display surface S1 is not in the upward facing state (the other surface is in the upward facing state) (no at step S102), the flow proceeds to step S114 (fig. 21) described later.

On the other hand, when it is determined that the display surface S1 is in the upward facing state (step S102: YES), the display control section 15 performs display control of the display panel 111 so as to start image display on the side of the display panel 111 (display surface S1) (step S103). Subsequently, the display control section 15 performs display control so as to fix image display on the display panel 111 side (step S104). Subsequently, the display control section 15 performs display control of the display panel 111 so as to start information display (for example, information indicating "power consumption increase" or "high-definition image quality mode start") on the display surface S1 (step S105).

Subsequently, the display control section 15 performs display control of the display panel 111 so as to end the information display on the display surface S1 (step S106 in fig. 20). Note that the time period for which this information is displayed is, for example, on the order of several seconds. Subsequently, the display control section 15 acquires the operation signal Sm from the

operation sections

12a, 12b, and 12c (step S107). Subsequently, the display control section 15 determines whether an instruction to end the image display is provided by the user based on the operation signal Sm (step S108). Here, when it is determined that an instruction for ending the image display is provided (step S108: yes), the flow proceeds to step S109 and step S110 (fig. 24) corresponding to the ending processing.

In this end processing, the display control section 15 performs display control of the

display panels

111 and 112 so that the display of the image on the display panel 111 (display surface S1) side ends and the display of the image on the display panel 112 (display surface S2) side also ends (step S109 and step S110 in fig. 24). Thereafter, the power of the electronic apparatus 1 enters an OFF state, and a series of steps in the display control shown in fig. 19 to 24 ends.

On the other hand, when it is determined in step S108 that an instruction for ending the image display is not provided (step S108: NO), the display control portion 15 subsequently determines which of the first to third display modes is the selected display mode based on the operation signal Sm (step S111). Note that here, the display surface S1 is in the upward facing state, and therefore, as described above, one of the first to third display modes can be set.

Here, when it is determined in step S111 that the first display mode is selected, the first display mode has been created in a state where the display control of the display panel 112 is not performed (the driving voltage Vd2 is not supplied), and therefore, the flow returns to step S101 (fig. 19).

Alternatively, when it is determined in step S111 that the second display mode is selected, the display control section 15 performs display control of the display panel 112 so as to start the second display mode. Specifically, as described above, the image display is started on the display panel 112 side so that the entire pixel area in the display panel 112 is in the monochrome reflective display state (step S112). Thus, the second display mode is started, and subsequently, the flow returns to step S101 (fig. 19).

Alternatively, when it is determined in step S111 that the third display mode is selected, the display control section 15 performs display control of the display panel 112 so as to start the third display mode. Specifically, as described above, the image display is started on the display panel 112 side, so that the partial monochrome reflective display and the transparent state are created in the display panel 112 (step S113). Accordingly, the third display mode is started, and then the flow returns to step S101 (fig. 19).

Here, when it is determined in step S102 that the display surface S1 is not in the upward facing state (step S102: no), the display control portion 15 subsequently performs the following determination based on the operation signal Sm. That is, it is determined whether the display surface S2 is in the upward facing state (step S114 in fig. 21).

Here, when it is determined that the display surface S2 is not in the upward facing state (the surfaces other than the display surfaces S1 and S2 are in the upward facing state) (step S114: no), the display control section 15 subsequently acquires the operation signal Sm again from the

operation sections

12a, 12b, and 12c (step S115). Subsequently, based on the operation signal Sm, the display control section 15 determines whether an instruction for performing image display (bidirectional display, or double-sided display) on the display surfaces S1 and S2 is provided by the user (step S116). Here, when it is determined that an instruction for performing the bidirectional display is not provided (step S116: no), the flow returns to the first step S101 (fig. 19).

On the other hand, when it is determined that an instruction for performing bidirectional display is provided (step S116: YES), the display control section 15 performs display control of the

display panels

111 and 112 so as to start bidirectional display. Specifically, first, the display control section 15 performs display control of the display panel 111 so as to cancel fixation of the image display on the side of the display panel 111 (the display surface S1) (step S117). Subsequently, the display control section 15 performs display control of the

display panels

111 and 112 so as to start image display on the display panel 111 side and also start image display on the display panel 112 (display surface S2) side (steps S118 and S119). Accordingly, the bidirectional display starts, and then the flow returns to step S101 (fig. 19).

Here, when it is determined in step S114 that the display surface S2 is in the upward facing state (step S114: yes), the display control section 15 performs display control of the display panel 112 so as to start image display on the display panel 112 (display surface S2) side (step S120). Subsequently, the display control section 15 performs display control so as to fix image display on the display panel 112 side (step S121). Subsequently, the display control section 15 performs display control of the display panel 112 so as to start information display (for example, information indicating "power consumption reduction" or "transmission mode start" as described above) on this display surface S2 (step S122).

Subsequently, the display control section 15 performs display control of the display panel 112 so as to end the information display on the display surface S2 (step S123 in fig. 22). Note that the time period for which this information is displayed is also, for example, on the order of several seconds. Subsequently, the display control part 15 acquires the operation signal Sm from the

operation parts

12a, 12b, and 12c (step S124). The display control section 15 then determines whether an instruction to end the image display is provided by the user based on the operation signal Sm (step S125). Here, when it is determined that an instruction for ending the image display is provided (step S125: yes), the flow proceeds to the ending processing described above (step S109 and step S110 in fig. 24).

On the other hand, when determining that the instruction for ending the image display is not provided (step S125: NO), the display control section 15 subsequently determines whether the fourth display mode is selected based on the operation signal Sm (step S126). Note that here, the display surface S2 is in the upward facing state, and therefore, as described above, one of the fourth to sixth display modes can be set.

Here, when it is determined that the fourth display mode is selected, the fourth display mode has been created in a state where the display control of the display panel 111 is not performed (the driving voltage Vd1 is not supplied), and therefore, the flow returns to step S101 (fig. 19).

On the other hand, when determining that the fourth display mode is not selected, the display control section 15 subsequently acquires the ambient brightness Di detected in the illuminance sensor 14 (step S127). The display control section 15 then determines whether the ambient brightness Di is less than a predetermined threshold value Dth (Di < Dth) (step S128 in fig. 23). Note that the threshold Dth is, for example, an ambient illuminance set for determining whether or not it is possible to read a book under external light. However, the threshold Dth is not limited to a fixed value, and may be a variable value that can be changed to an arbitrary value according to the situation. Here, when it is determined that the ambient illuminance Di is the threshold value Dth or more (Di ≧ Dth) (step S128: no), the ambient illuminance is relatively high (relatively bright lighting environment), and therefore, the fourth display mode is automatically selected (set) for the above-described reason. Therefore, thereafter, as described above, since the fourth display mode has been created in this state, the flow returns to step S101 (fig. 19).

On the other hand, when it is determined that the ambient illuminance Di is less than the threshold Dth (Di < Dth) (step S128: yes), the ambient illuminance is relatively low (relatively dark lighting environment), and therefore, the fifth or sixth display mode is automatically selected for the above-described reason. In this case, the display control section 15 then performs display control of the display panel 112 so as to perform tone correction in image display on the side of the display panel 112 (the display surface S2) (step S129). The display control section 15 then performs display control of the display panel 111 so as to start image display on the display panel 111 (display surface S1) side as a precondition for starting the display mode in the fifth or sixth display mode (step S130).

Subsequently, based on the operation signal Sm acquired in step S124, the display control portion 15 determines whether or not the fifth display mode is selected (step S131). Here, when it is determined that the fifth display mode is selected (step S131: YES), the display control section 15 performs display control of the display panel 111 so as to start the fifth display mode. Specifically, as described above, the image display on the display panel 111 side is changed so that the entire pixel region in the display panel 111 is in the monochrome display state (step S132). Accordingly, the fifth display mode is started, and then the flow returns to step S101 (fig. 19).

On the other hand, when it is determined that the sixth display mode is selected (step S131: NO), the display control section 15 performs display control of the display panel 111 so as to start the sixth display mode. Specifically, the image display on the display panel 111 side is changed so that the partial monochrome display state and the transparent state are created in the display panel 111 as described above (step S133). Therefore, the sixth display mode is started, and then the flow returns to step S101 (fig. 19). This concludes the description of a series of steps of the display control shown in fig. 19 to 24.

As described above, in the present embodiment, the two types of

display panels

111 and 112 are provided in the display section 11, and therefore, image display can be realized on the display surfaces S1 and S2 facing each other by allowing the device functions in the

respective display panels

111 and 112 to complement each other. Therefore, improvement in user convenience can be achieved.

Further, since such image display (double-sided display) on the display surfaces S1 and S2 is possible, it is possible to enlarge the display area in the display section 11 (electronic apparatus 1) to a large extent. Therefore, it is possible to display information with many added values, so that further improvement in user convenience can be achieved.

Further, for example, when the display panel 111 and the display panel 112 display respective different images overlapped with each other, it is possible to display information with more added value, so that further improvement in user convenience can be achieved.

<2. modification >

Subsequently, modifications (modification 1 and modification 2) of the above-described embodiment will be described. Note that the same components as those in the above-described embodiment will be provided with the same reference numerals as those of the embodiment, and the description thereof will be omitted as appropriate.

[ modification 1]

(configuration)

Fig. 25 schematically shows a configuration example of an electronic apparatus with a display device (electronic apparatus 1A) according to modification 1 in a plan view (X-Y plan view). In the electronic apparatus 1A (display device) of the present modification, the display portion 11 is configured to be foldable into two parts (two display areas) (see an arrow P3 in fig. 25). Specifically, the display portion 11 is configured to include a display portion 11a (first display portion), a display portion 11b (second display portion), and a hinge portion 110.

As with the display portion 11 described in the embodiment, the display portion 11a has the following configuration: the display panel 111 disposed on the side of the display surface S1 and the display panel 112 disposed on the side of the display surface S2 overlap each other in the thickness direction (Z-axis direction). Similarly, the display portion 11b also has the following configuration: the display panel 111 disposed on the side of the display surface S1 and the display panel 112 disposed on the side of the display surface S2 overlap each other in the thickness direction. Note that, in this example, in the

display section

11a or 11b, the

display panels

111 and 112 are arranged so that the display surface S1 faces inward and the display surface S2 faces outward in a state where the entire display section 11 is folded (closed state).

The hinge portion 110 is a portion provided to connect the two

display portions

11a and 11b in a folded manner (freely opened-closed). In this example, the hinge portion 110 is arranged to extend on the Y axis so that the rotation axis corresponds to the Y axis when folded (opened and closed).

(actions and effects)

In the electronic apparatus 1A having such a configuration, similar effects that are obtained by actions similar to those of the electronic apparatus 1 of the embodiment can be basically obtained.

Further, in this electronic apparatus 1A, specifically, since the display portion 11 is folded into two parts, various display modes described below can be realized according to, for example, a use situation, so that further improvement in user convenience can be realized.

Specifically, for example, as shown in fig. 26A, when it is detected that the

display portions

11a and 11b are in the folded and closed state, the display control portion 15 performs, for example, the following display control. That is, the display control section 15 performs the above-described display control so that the entire pixel region of each of these

display sections

11a and 11b of each of the

display panels

111 and 112 is in a transparent state.

It should be noted that whether the

display portions

11a and 11b are in the folded state (whether in the closed state or the open state) is detected based on the mechanism state of the hinge portion 110, for example, and a detection signal indicating the state thereof is supplied to the display control portion 15, for example.

In this example shown in fig. 26A, both the

display portions

11a and 11b are in a transparent state (light transmitting state). Therefore, for example, in a state such as a standby state of the electronic apparatus 1A (display device), when viewed from the front or the rear, the entire display portion 11 is a transparent panel, so that a display design with an improved luminance impression can be realized. Further, in this case, four display panels (two for the display panel 112 and two for the display panel 111) are overlapped with each other as a whole in the display section 11, and therefore, by setting any one of the first, third, fourth, and sixth display modes in each of the

display sections

11a and 11b, for example, the following effects can also be expected. In other words, by displaying three or four different types of images overlapping each other, information with more added value can be displayed. Further, by displaying the same three or four images overlapped with each other, further improvement in user convenience can be achieved.

Further, for example, as shown in fig. 26B, when a state in which the display portions 11a and 11B are opened in the up-down direction (in this example, the vertical direction or the Y-axis direction) with the hinge portion 110 interposed therebetween is detected, the display control portion 15 performs, for example, the following display control. That is, the display control section 15 performs the above-described display control so as to perform the image display of the transparent state in the display surface S1 or the display surface S2 (in this example, the display surface S1) in one of the

display sections

11a and 11b (in this example, the display section 11 a). Specifically, display control of the

display panels

111 and 112 in the display section 11a is performed so as to perform, for example, image display by any one of the first, third, fourth, and sixth display modes (in this example, the first or third display mode). Further, the display control section 15 performs the above-described display control on the other (in this example, the display section 11b) so as to perform image display in a non-transparent state on the display surface S1 or the display surface S2 (in this example, the display surface S1). Specifically, display control of the

display panels

111 and 112 in the display section 11b is performed so as to perform, for example, image display by the second or fifth display mode (in this example, the second display mode).

In this example shown in fig. 26B, image display in the transparent state is performed in the display section 11a, and image display in the non-transparent state is performed in the display section 11B, and therefore, for example, one of various usage manners such as described below is realized, so that further improvement in user convenience can be realized. Specifically, for example, when a small image pickup image sensor (for example, an image pickup device such as a CMOS (complementary metal oxide semiconductor)) is arranged on the display surface S2 side of the display portion 11a or the display portion 11b, the following usage can be achieved. That is, for example, a usage pattern that displays screens of various application programs in the display portion 11b while using the display portion 11a as an electronic viewfinder (a large screen with high definition) in the image pickup device can be realized.

On the other hand, for example, as shown in fig. 26C, when detecting a state in which the

display sections

11a and 11b are opened in the lateral direction (in this example, the horizontal direction, the X-axis direction) with the hinge section 110 interposed therebetween, the display control section 15 performs, for example, the following display control. That is, the display control section 15 performs the above-described display control so as to perform image display in a non-transparent state on a common display surface (in this example, the display surface S1) of each of these

display sections

11a and 11b, which is one of the display surface S1 and the display surface S2. Specifically, display control of the

display panels

111 and 112 of each of the

display sections

11b and 11b is performed so as to perform, for example, image display by the second or fifth display mode (in this example, the second display mode).

In this example shown in fig. 26C, image display in a non-transparent state is performed on the usual display surface (display surface S1) of each of the

display sections

11a and 11b, and therefore, for example, one of various usage patterns such as described below is realized, so that further improvement in user convenience can be realized. Specifically, for example, by using the first to sixth display modes, when single image display (large screen display is realized by combining the two display surfaces S1) is performed on the entire common display surface in these

display sections

11a and 11b, further improvement in user convenience can be realized.

[ modification 2]

Fig. 27A and 27B schematically show a configuration example of an electronic apparatus with a display device (electronic apparatus 1B) according to modification 2 in perspective views, respectively. In the electronic apparatus 1B (display device) of the present modification, components such as the

display panels

111 and 112 in the display portion 11 have flexibility and are configured as a flexible thin display. Further, in this example, the entire electronic apparatus 1B includes the casing 10 exhibiting flexibility.

Thus, for example, as shown in fig. 27A, it is realized that the electronic apparatus 1B is stored and carried in a folded state (in a state such as a standby state) when not in use (see an arrow P4 in fig. 27A). Further, for example, when each of the display panels 111 and 1112 in the display section 11 is set to the transparent state (light transmitting state) as described above, for example, as shown in fig. 27A, a see-through folded state can be achieved when not in use.

On the other hand, for example, as shown in fig. 27B, when using (image display), it is realized to use the electronic apparatus 1B according to an arbitrary degree of bending (a deflected state or a bent state) including a flat state. Further, also in this case, image display is performed by arbitrarily setting one display mode of the above-described plurality of display modes (first to sixth display modes).

Here, in this electronic apparatus 1B, each of the

display panels

111 and 112 in the display section 11 has a configuration using a flexible substrate such as a resin film instead of a glass substrate. In addition, each device such as a driving device is configured using a flexible device such as an organic TFT. The housing 10 is also an exterior member having flexibility. Specifically, the case 10 is made of a material such as a resin film (transparent film) which is soft and has transparency (light transmittance) for displaying light, for example, an olefin resin.

In the electronic apparatus 1B having such a configuration, similar effects achieved by actions similar to those of the electronic apparatus 1 of the embodiment can be basically obtained.

Further, in particular, in this electronic apparatus 1B, since each of the components such as the

display panels

111 and 112 has flexibility, for example, the various use manners and display manners described above can be realized, so that further improvement in user convenience can be realized.

<3 > other modifications

The technique of the present disclosure is described above using the embodiments and the modification, but the technique is not limited to these embodiments and the like, and various modifications may be made.

For example, the embodiment and the like are described using a case as an example in which one of three display modes (first to third display modes or fourth to sixth display modes) is selected, but not limited thereto. In other words, one display mode can be selected from any two display modes among the three display modes. Further, the method of selecting the display mode in these cases is not limited to the method described in embodiment mode and the like, and one of a plurality of display modes may be selected (changed) using other methods.

Further, the plurality of display modes are also not limited to the six display modes (first to sixth display modes) described in the embodiment and the like, and other types of display modes may be added (or alternatively, set) and used.

Further, the embodiment and the like are described using specific types, configurations, and the like of each of the light emitting element and the light controlling element which are used as the display element of each of the display panels, respectively, but are not limited thereto. For example, a light emitting element other than the organic EL device and a light controlling element other than a liquid crystal device using cholesteric liquid crystal can be used as the display element. Further, the light emitting element may perform color image display by using, for example, a light emitting element that emits white light and three primary color filters (in this case, disposed above and below the light emitting element), instead of performing emission of each of the three primary colors (R, G, B). Further, in some cases, the image display in each display panel may be monochrome image display instead of the color image display described in the embodiment and the like.

Further, modification 1 is described above using as an example a case in which the display portion is foldable into two parts (the display portion includes two foldable display portions), but is not limited thereto. In other words, for example, the display portion may be foldable into three or more parts (the display portion may include three or more foldable display portions).

Further, the embodiments and the like are described using specific configurations of an electronic apparatus and a display device, but are not limited to those configurations. Specifically, for example, these configurations may be partially replaced by other configurations, or other configurations may be further added. Further, all the shapes, layouts, numbers, materials, and the like in each configuration are not limited to those described in the embodiments and the like, and other shapes, layouts, numbers, materials, and the like may be employed.

Furthermore, the various examples described above may be combined as desired and used as appropriate.

Further, the display apparatus of the present disclosure is applicable not only to the mobile device described as an example of the electronic device in the embodiment and the like, but also to various mobile devices (e.g., an electronic book, a notebook PC (personal computer), a mobile audio layer, a mobile movie player, a mobile phone, a wearable terminal, and the like). Further, the display device of the present disclosure is applicable not only to such mobile apparatuses, but also to various electronic apparatuses (e.g., television apparatuses (television receivers), lighting apparatuses, display devices placed in windows, mirrors, and the like, electronic signatures (digital signatures), car navigation systems, and the like).

It should be noted that the effects described in this specification are merely exemplary and not restrictive, and other effects may be possible.

It should be noted that the present technology may also have the following configuration.

(1) A display device, comprising:

a display section having a first display surface and a second display surface facing each other,

wherein the display portion includes:

a first display panel arranged on one side of the first display surface and including a plurality of light emitting elements, an

A second display panel arranged on one side of the second display surface and including a plurality of light control elements that respectively perform light control for controlling transmission or reflection of incident light, respectively perform reflection image display with reflection of incident light.

(2) The display device according to item (1), wherein,

the light emitting element outputs emitted light to a side of the first display surface and a side of the second display surface, and

the light control element performs the light control and the reflected image display with respect to incident light from a side of the first display surface and incident light from a side of the second display surface.

(3) The display device according to item (2), wherein in each of the first display panel and the second display panel, light transmittance is changed pixel by pixel in accordance with a driving voltage applied to the light-emitting element or the light-controlling element.

(4) The display device according to item (3), further comprising: a display control section configured to perform individual control of image display in the first display panel and the second display panel,

wherein the display control section performs the individual control so as to execute one display mode selected from a plurality of display modes with a pixel-by-pixel change in light transmittance.

(5) The display device according to item (4), wherein,

when image display of the light emitting elements is performed in at least a part of the pixel region of the first display panel,

the display control section performs the individual control so as to execute one display mode selected from at least two or more display modes among three display modes serving as a plurality of display modes, the modes including:

a first display mode in which the entire pixel region of the second display panel is in a transparent state by transmission of incident light using the light control element,

a second display mode in which the entire pixel region of the second display panel is in a monochrome reflection display state by reflection image display based on incident light from one side of the first display surface with the light control element, and

a third display mode in which, in the second display panel, the vicinity of a pixel region corresponding to a display pixel region in the first display panel is in the monochrome reflective display state, and the vicinity of a pixel region corresponding to a transparent pixel region as a non-display pixel region in the first display panel is in a transparent state.

(6) The display device according to item (5), wherein,

can be respectively adjusted at will

Setting of colors in a monochrome reflective display state in the second display mode and the third display mode, an

Setting a portion of a pixel region in the monochrome reflective display state or the transparent state in the third display mode.

(7) The display device according to item (5) or item (6), wherein one display mode is selected from at least two or more display modes of the first display mode to the third display mode in accordance with an operation signal input from outside.

(8) The display device according to any one of the items (5) to (7), wherein,

when the state in which the first display surface faces upward is detected,

the display control section performs individual control so as to perform image display in at least a part of the pixel region of the first display panel.

(9) The display device according to any one of the items (4) to (8), wherein,

when reflected image display based on incident light from one side of the second display surface is performed by the light control element in at least a part of the pixel region of the second display panel,

the display control section performs individual control so as to execute one display mode selected from at least two or more display modes among three display modes serving as a plurality of display modes, the modes including:

a fourth display mode in which the entire pixel region of the first display panel is in a transparent state by the light emitting element being brought into a non-emission state,

a fifth display mode in which the entire pixel region of the first display panel is in a monochrome display state by the light emitting element being brought into an emission state, an

A sixth display mode in which, in the first display panel, the vicinity of a pixel region corresponding to a display pixel region in the second display panel is in a monochrome display state, and the vicinity of a pixel region corresponding to a transparent pixel region as a non-display pixel region in the second display panel is in a transparent state.

(10) The display device according to item (9), wherein,

can be respectively adjusted at will

Setting of colors in a monochrome display state in the fifth display mode and the sixth display mode, an

Setting a part of a pixel region in a monochrome display state or a transparent state in the sixth display mode.

(11) The display device according to item (9) or item (10), wherein one display mode is selected from at least two or more display modes from the fourth display mode to the sixth display mode in accordance with an operation signal input from outside or detected ambient illuminance.

(12) The display device according to item (11), wherein,

when the ambient illuminance is equal to or greater than a threshold value, the fourth display mode is selected as the one display mode, and

when the ambient illuminance is less than the threshold, selecting a fifth display mode or a sixth display mode as the one display mode.

(13) The display device according to any one of the items (9) to (12), wherein,

when it is detected that the second display surface is in an upward facing state,

the display control section performs the individual control so as to perform the reflection image display in at least a part of the pixel region of the second display panel.

(14) The display device according to any one of the items (4) to (13), wherein,

when it is detected that the display device is in a standby state,

the display control section performs the individual control so as to allow the pixel region of each of the first display panel and the second display panel to be in a transparent state.

(15) The display device according to any one of the items (1) to (14), wherein,

the display section includes:

a first display section and a second display section having a first display panel and a second display panel, respectively, an

A hinge part configured to connect the first display part and the second display part in a foldable manner.

(16) The display device according to item (15), wherein,

when it is detected that the first display part and the second display part are in the folded and closed state,

in each of the first display section and the second display section, display control is performed so as to allow a pixel region in each of the first display panel and the second display panel to be in a transparent state.

(17) The display device according to item (15) or item (16), wherein,

when a state in which the first display section and the second display section are opened in the up-down direction with the hinge section interposed therebetween is detected,

performing display control so as to perform image display in a transparent state in the first display surface or the second display surface in one of the first display section and the second display section and to perform image display in a non-transparent state in the first display surface or the second display surface in the other of the first display section and the second display section, and

when a state in which the first display section and the second display section are opened in the lateral direction with the hinge section interposed therebetween is detected,

performing display control so as to perform image display in a non-transparent state in a common display surface of each of the first display section and the second display section, the common display surface being one of the first display surface and the second display surface.

(18) The display device according to any one of the items (1) to (17), wherein each of the first display panel and the second display panel has flexibility.

(19) The display device according to any one of the items (1) to (18), wherein,

the light emitting element is an organic electroluminescent element, and

the light control element includes cholesteric liquid crystal.

(20) An electronic device, the electronic device comprising:

a display device for displaying the image of the object,

wherein the display device includes:

wherein the display portion includes:

This application is based on and claimed in priority from japanese patent application No. 2013-197791, filed in 2013, month 9, 25, to the office of this patent, the entire contents of which are incorporated herein by reference.

It should be understood by those skilled in the art that various changes, combinations, sub-combinations and alterations can be made according to design requirements and other factors insofar as they come within the scope of the appended claims or the equivalents thereof.

Claims

1. An electronic device, comprising:

a first display panel including a plurality of first pixels respectively including a plurality of light emitting elements;

the second display panel includes a plurality of second pixels including a plurality of light control elements; and

a display control section configured to control image display of each of the first display panel and the second display panel, respectively;

wherein, the display control part includes:

a first display driving circuit configured to drive the first display panel;

a second display driving circuit configured to drive a second display panel; and

a control circuit configured to operate the first display driving circuit and the second display driving circuit,

wherein the first display panel further comprises a first driving substrate,

at least one of the light emitting elements includes a first electrode, a second electrode, and an organic light emitting layer,

a first driving substrate, a first electrode, an organic light emitting layer and a second electrode are sequentially stacked,

at least the second electrode has transparency so that light emitted from the organic light emitting layer is extracted through the second electrode, and

the second electrode is provided in common to the plurality of light emitting elements of the first pixel,

wherein the second display panel further comprises a second driving substrate,

at least one light controlling element includes a pixel electrode, a common electrode and a liquid crystal material,

a second driving substrate, a pixel electrode, a liquid crystal material and a common electrode are sequentially stacked,

each of the common electrode and the pixel electrode has transparency so that each of the light control elements controls transmission of light through the second display panel, and

the second electrode is provided in common to the plurality of light emitting elements of the first pixel;

wherein, in each of the first display panel and the second display panel, light transmittance is changed on a pixel-by-pixel basis in accordance with a driving voltage applied to the light emitting element or the light control element.

2. The electronic device of claim 1, further comprising a first sensor operatively coupled to the display control and configured to detect a gesture of the electronic device, wherein the display control is configured to control the display of the image of each of the first and second display panels in accordance with the gesture detected by the first sensor.

3. The electronic device of claim 1, further comprising a second sensor operatively coupled to the display control and configured to detect an ambient brightness of the electronic device, wherein the display control is configured to control the display of the image of each of the first and second display panels as a function of the ambient brightness detected by the second sensor.

4. The electronic device according to claim 2, the display control section being configured to (i) display a specific image on the first display panel, and (ii) display a specific image on the first display panel

(ii) The display state of the second display panel is changed to display a specific image according to the change in the posture detected by the first sensor.

5. The electronic device of claim 1, wherein the first display panel faces a first direction and the second display panel faces a second direction different from the first direction.

6. The electronic device of claim 5, wherein the first direction is an opposite direction from the second direction relative to the electronic device.

7. The electronic device of claim 6, wherein a back surface of the first display panel is disposed on a back surface of the second display panel.

8. The electronic device of claim 7, wherein the light control element is configured to control transmission of light emitted from the organic light emitting layer and passing through the second display panel.

9. The electronic device according to claim 1, wherein the first electrode has transparency so that light emitted from the organic light-emitting layer is extracted through the first electrode and the second electrode.